Security has become more important in all aspects of society as threats through deception have become more prevalent. Printed documents are no exception. Printed media has been the long standing vehicle for communication of many official declarations such as stocks and bonds, legal documents such as wills, currency, licenses of various sorts, official records of transaction such as the sale or purchase of an item, documentation declaring value such as for jewelry, documentation declaration authenticity such as for art work, lottery tickets, and so forth. In recent times, counterfeit technologies have improved. High quality scanners to reproduce documentation are readily available at very low cost as are high quality output devices that can reproduce scanned images with a high level of accuracy. This can make it difficult to identify counterfeit material without significant forensic effort.
Many of the above mentioned applications have a limited print volume, often requiring only a single copy of a printed document. However, in addition to these applications, there are print production applications that may result in a lower monetary loss per counterfeit item but cumulatively can be most significant. Such applications occur frequently in packaging, ticketing, coupons, labeling, and so forth. A simple bar code in wide spread use today for such applications is not sufficient to verify authenticity because they are easily reproduced.
There remains a need for methods of producing authentic documentation that can easily be identified as such by providing overt identifying attributes that are very difficult or impossible to reproduce, and that can be produced using methods that are practical for high speed commercial digital printing devices, such as continuous inkjet printers.